[1] : The Collaborative International Dictionary of English v.0.48

echinodermata \echi`noder"mata\
   -ekimac`n-od~er"m.at.a, n. pl. nl., fr. gr.
   'echi^nos hedgehog, sea urchin + de`rma, -atos, skin.
   zo"ol.
   one of the grand divisions of the animal kingdom. by many
   writers it was formerly included in the radiata. written
   also echinoderma.
   1913 webster

   note: the species usually have an exterior calcareous
         skeleton, or shell, made of many pieces, and often
         covered with spines, to which the name. they may be
         star-shaped, cylindrical, disk-shaped, or more or less
         spherical. the body consists of several similar parts
         spheromeres repeated symmetrically around a central
         axis, at one end of which the mouth is situated. they
         generally have suckers for locomotion. the group
         includes the following classes: crinoidea, asterioidea,
         ophiuroidea, echinoidea, and holothurioidea. see these
         words in the vocabulary, and also ambulacrum.
         1913 webster
see also:
echinoderma ambulacrum 

[2] : WordNet (r) 2.0

echinodermata
     n : radially symmetrical marine invertebrates including e.g.
         starfish and sea urchins and sea cucumbers syn: phylum
         echinodermata
see also:
phylum echinodermata 

Echinodermata >> E Words
Echinodermata, definition of term: Echinodermata
echinodermata_pag1.html